22 



aperture pyrlform, half the length of the shell ; columella fold 

 conspicuous ; lip thin. Length, ^^^ inch, breadth, ^ inch. Hab. 

 Oahu. 



Paludina porrecta. Shell elongated, turreted, thin, smooth, 

 greenish, imperforate ; whorls six, very convex ; suture deep ; 

 aperture ovate ; lip continuous. Length, ^^^ inch, diameter less 

 than i\ inch. Hab. Oahu. 



Paludina anthracina. Shell elongate-conic, thin, smooth, 

 brown, covered with a black pigment, imperforate ; whorls five, 

 convex ; aperture subovate ; lip continuous, acute. Length, ^j 

 inch, diameter, y^g- inch. Hab. Tortola. 



Sigaretus filicatus. Shell orbicular-ovate, rather thick, 

 white, umbilicated ; whorls about two, the last two of which 

 composes nearly all the shell ; external surface beautifully sculp- 

 tured, being covered with triangular ribs placed longitudinally, 

 and numerous transverse strise ; aperture rounded oval. Length, 

 I inch, breadth nearly equal to the length. Hab. Zanzibar, 

 eastern Africa. 



Solarium implexum. Shell depressed, subdiscoid, grayish 

 white, with a few brown spots ; whorls three, flattened, with five 

 rounded, revolving ridges on each, intersected by numerous, im- 

 pressed, transverse striae ; aperture circular ; umbilicus large and 

 deep. Diameter, y\ inch. Hab. Oahu. 



Solarium cyclostomum. Shell orbicular, convex, ash colored 

 or greenish ; whorls four to five, convex, with five, revolving 

 ridges, intersected by impressed transverse striae ; suture, deep ; 

 aperture circular ; umbilicus deep ; operculum horny, spiral. 

 Diameter, f^j inch. Hab. Oahu. 



Turbo rubricinctus. Shell minute, orbicular-conical, white, 

 with numerous, impressed, revolving bands of a superb vermilion 

 color, imperforate ; whorls four, convex ; aperture circular. 

 Diameter, ^V ifich. Hab. Oahu. 



Cerithium gracilentum. Shell turreted, fusiform, brown and 

 white, spotted or banded, whorls ten to twelve, flattened, with 

 four unequal, acute, elevated revolving ridges on each ; aperture 

 sinistral, subovate ; canal tubular, deflected, twisted. Length of 

 the largest, -^^ inch, diameter, ^ inch. Hab. Oahu. 



Cerithium maculosum. Shell conical, white, with zig-zag 

 lines and spots, polished ; whorls six, angular, tuberculated, trans- 

 versely striated ; aperture ovate, ending in a notch. Length, 

 about ^ inch, diameter, -i inch. Hab. Oahu. 



